Valve construction for grounded aviation trainers



4 Sheets-Sheet 1 INVENTOR.

I 1 AT;ORNEYS NW rm H IM I I wnu May 10, 1949. s. A. DOUGLAS VALVE CONSTRUCTION FOR GROUNDED AVIATION TRAINERS Filed Nov. 50, 1945 Q P ml 3 SAMUEL ARTHUR DOUGLAS ;%Mz%w May 10, 1949. s. A. DOUGLAS 2,469,918

VE CONSTRUC D AVIATION TRAINERS May 10, 1949. s. A. DOUGLAS 2,469,918

VALVE CONSTRUCTION FOR GROUNDED AVIATIOIi TRAINERS Filed Nov. so, 1945] 4 Sheets-Sheet 5 M8 |/Ba=3 =1"" I54 SAMUEL ARTHUR DOUGLAS AT RNEYS May 10, 1949. s. A. DOUGLAS 6 VALVE CONSTRUCTION FOR GROUNDED AVIATION TRAINERS Filed Nov. 30, 1945 4 Sheets-Sheet 4 iilllllllllllllilllllllllllir AIR 6 ans-0 2 OUTPUT SAMUEL" $1PV9MRP BY%11MX{ w F164 I Wilffi Patented May 10, 1949 VALVE CGNSTRUCTION FOR GROUNDED AVIATION TRAINERS Samuel Arthur Douglas, Union, N. Y., assignor to Link Aviation, Inc., a corporation of. New York Application November 30, 1945-, Serial No. 631,906

7 Claims.

1 This. invention relates to. grounded aviation trainers of the type disclosed in U. S. Patents 1,825,462- and 2,099,857, issued to Edwin A. Link. More particularly; .this invention relates to an improvedmain valveconstruction for use in such trainers.

As disclosed in the two above mentioned patents, and as is well known to the prior art, trainers of the type being considered include four collapsible-expansible bellows connected to a suitable vacuum source, such as a turbine, and to the atmosphere through what may be termed the fuselage control valves. These valves are operated by the control stick (or control column) in the trainer in suchna manner that when the control stickis .moved ahead, the elevator valve isoperated so that vacuum is admitted to the forward pitching bellows and atmosphere to the rearpitching bellows, resulting in a diving of the fuselage which is controlled by the bellows. On theother hand, a rearward movement of the control stickoperates the velevatorcontrol valve so thatvacuum is admitted to the rear pitching bellowsandatmosphere to theirontpitching bellows, resulting the fuselages assuming a climbing attitude. Whenthe control stick ismoved to the left of itsneutral position it operates the aileron valve which. admits vacuum to the left banking bellows and atmosphere-tothe right banking bellows, causing the fuselage to bank to the left. On the-other hand, a movement of the control stick to the rig-htof its neutral position operates theaileron valve so that vacuum is admitted to the right banking bellows and atmosphere tothe left banking bellows, resulting in a bankingto the right of the fuselage.

At thesame time trainers of the type being consideredemploy a. doubleacting turning motor which is connected vtothesource of vacuum and to the atmosphere througha rudder-valve which is. controlled bythe rudder pedals which are conventionally placed in these trainers. When the left rudderpedal is pressed forward, therudder valve is operated to admit vacuum to one side of the turning motor and atmosphere to the other, resulting in a turning-of thetrainer towards the left. 0n the other hand, when the right rudder pedalis pressed forward the rudder valve is operated so that vacuum and. atmosphere are introducedin theiopposite-sides of the turning motor, and the trainer isrotated toward the right.

Also, these trainers includeauxiliary valve arrangements so that the fuselage will automaticallvbankzinhe di ection of its turning. automatically turn in the direction of its banking,

and sothat thenoseiof the fuselage will automatically drop whenever the fuselage is turning-just as occurs in the case of a plane in actual flight.

It is a principal object of this invention to replace the main control valves as well as the auxiliary valves-known to the prior art by a more compact valve assembly which may be easily manufactured, assembledand adjusted, andwhich Willeliminate alarge portion of the linkages used in the prior art trainers to operate the various valves in order that the proper efiects may be achieved.

,In general, this invention. comprises four valve sections placed vertically one above and in con.- tact with the adjacent sections, together with a platewhich is. movable in a. single plane by the movementso-f-thecontrol stick in order to operate the adjacent valve sections so as toproduce the basic -climbing and diving movements in response to the control stick movements.

Then my invention also includes means for moving'the top valve section relative to the plate whichis controlled by ,the control stick in order that the pitching attitude of the fuselage may be made dependent upon the factor of assumed air speed.

The basic fuselage .turning movements are accomplished by rotation of the lowermost valvesection in response to movements of the rudder pedals, while the automatic bank with turn and nose down with turn movements are also initiated by the rotation of the lowermost rudder valve section. The automatic turn with bank action is introduced by the rotation of the section lying immediately above the rudder valve section, this section being referred to as the auxiliary valve section.

The section immediately above the auxiliary effect valve section comprises six radially formed chambers, two of which connect with the pitching bellows, two of which connect with the banking bellows and two of which connect with the turning motor. Vacuum and atmosphere are selectivelyadmitted to the six radial chambers of the main valve section in accordance with the movements 1of-the control stick which selectively opensandcloses the ports in the uppermost valve section, and in accordance with the movements imparted to the auxiliary effect valve section and to the rudder valve section.

Inorder that the exact nature of this inventionmay be better understood, reference is made to the accompanying drawings, wherein "l. isa general exterior view of trainers of the type "being considered showing the fuselage;

f; pitching and banking bellows, the turning motors, turbine, desk and conventional flight recorder.

Fig. 2 is a perspective view showing the control stick, the location of the main valve assembly, the main universal joint, the stationary base, rotatable carriage, turning motors and the pitching and banking bellows.

Fig. 3 is an exploded sectional view of the main valve assembly with which this invention is primarily concerned.

Fig. 3A is a top view of the main valve section, showing the six circumferentially spaced chambers.

Fig. 3B is a top view of the auxiliary effect valve section.

Fig. 4 is a perspective view showing the linkage interconnecting the auxiliary effect valve section with the universal joint, and

Fig. 5 is a top view of the plate attached to the top of the attitude valve section, together with the means for moving this section in accordance with the instant assumed air speed.

General description Referring now to Figs. 1 and 2, the normally stationary base of the trainer is designated l and comprises a plurality of beams suitably fixedly attached to one another, as by bolts. A plurality of rollers II are provided in order that the entire training unit with the exception of the desk I2 and its associated elements may be manually moved from position to position. However, during operation of the training device the base IE remains stationary. Fixedly attached to the base members [5 is the main hub IS in which the main spindle I4 is rotatably mounted. Afiixed to the main spindle [4 for rotation therewith are the horizontal cross arms I5 and aifixed to the outer end of each of these cross arms is the upper end of one of the depending members It, the lower ends of which support the carriage l7. Carriage ill in turn supports the forward pitching bellows 18, the rear pitching bellows IS, the left banking bellows and the right banking bellows 2i. The lower end of each of these four bellows is afiixed to the carriage I! while the upper end of each of these bellows is afixed to the floor or bottom side of the fuselage 22. Carriage l1 also supports the two schematically shown turning motors 23 which drive the pulley 2d. Pulley 24, by means of the turning belt 25 which encircles the main hub l3, may rotate the carriage ll, the four bellows, the fuselage 22 and all associated elements, including the turning motors 23 themselves, indefinitely in either direction according to the positions of the rudder pedals, in a manner more fully described hereinafter. The turning motors 23 are of the pneumatic type such as are extremely well known in the art. The sub-frame of the fuselage 22 is designated 21 and it will be seen that this frame is sup-ported by the universal joint which in turn is held by the spindle l4, the universal joint 28, being provided in order that the fuselage 22 may be dived, climbed and banked to the left or right with respect to the stationary base Ill. Diving and climbing movements of the fuselage 12 are sometimes hereinafter referred to as pitching.

It will therefore be appreciated that the fuselage 22 is mounted in a manner to permit indefinite rotation in either direction relative to the stationary base [6 in order that the turning to the left or right of a plane in actual flight may be simulated; and further, that the fuselage may be pitched and banked relative to the stationary about the longitudinal axis 38.

4 base [0 within the limits of the apparatus, in order to simulate the pitching and banking of a plane in actual flight.

An oval enclosing member 29 is aifixed to the rotatable carriage I! in order to improve the exterior appearance of the training device.

Upon the desk 12 is the recorder 30 which travels over the chart 3! in a direction dependent upon the assumed track of the fuselage I 2 and at a speed dependent upon the assumed ground speed of the fuselage, in order that a permanent record of the assumed course of flight of the fuselage 22 may be made. This recorder is well known to the prior art and is completely described in U. S. Patent 2,179,663, issued to Edwin A. Link. Also carried by the desk I2 is the instructors instrument panel 32 having a plurality of instruments to which the instructor may refer in order to ascertain the assumed air speed, assumed vertical speed, assumed altitude, and other assumed conditions of flight of the fuselage 22.

Fuselage banking, pitching and turning valve assembly Reference is now made to Fig. 3 which is an exploded perspective view of the fuselage pitching, banking and turning control valves.

In Fig. 3 portions of the fuselage sub-frame 21 are shown and it will be seen that the casting 33 is afiixed to frame 27 by means of the bolts 34. Integral with casting 33 are the two ears 35 (only one shown), and each of these ears has rotatably mounted therein a stud 36, the axis 38 of studs 36 extending longitudinally of the fuselage 22. The ear 35 and stud 36 shown in Fig. 3 are upon the foremost side of casting 33 as it is oriented within fuselage 22, i. e., toward the head of the fuselage. Each of the studs 36 is affixed in the gimbal ring 31 so that this gimbal ring can pivot The lower end of the control stick 39 in turn is pivotally held by the gimbal ring 31 for movement about the transverse axis 45. It will therefore be appreciated that the control stick 39 may be universally moved with respect to the casting 33. In Fig. 1 it will be seen that the control stick 39 is mounted directly ahead of the students seat 4| and the instructors seat is designated 4la.

Still referring to Fig. 3 it will be seen that the member 42 is provided, this member being integral with the lower end of the control stick 39. Integral with the member 42 is the upper portion 43 of the universal joint designated generally by 44a, the lower portion of this universal joint being numbered 45. The lower enlarged portion of member 45 is designated 46, is slotted at 41, and is movably mounted within the hub 48 integral with the circular cap 49 which in turn is integral with the square plate 50. A pin 5| passes through the hub 48 as well as the slot 41 in order to prevent rotation of the hub 48, cap 49 and. plate 50. However, portions 45 and 46 of the universal joint are vertically movable with respect to the hub 48.

Still referring to Fig. 3, it will be seen that integral with the lower side of casting 33 are four depending member 52, each of which is interiorly threaded for the reception of one of the four studs 53. Each of the studs 53 passes through the extensions 54 of the main valve section designated generally by 56 and a nut 51a is placed upon the lower end of each of the studs 53. Accordingly, the main valve section 56 is supported by the casting 33 in fixed relationship at all times.

,,Fig. 1.

the lower portion f Fig. 3. ametal tube .511 (having .a plurality of holes 58 :therein "is prolvlded, and afiixed upon'the Zlower end of tube :51 is the collar .69 by means of set screw 60. Tube 5.! extends :through collar '59, the portion f tube 51 below this .collar bein solid Walled, and the upper end of the flexible hose 6i encircles the lower endof tube '51. Tube 61 Icon- .nects with the conventional turbine 62 seen in This turbine is mounted upon the rotatable carriage ,ll seen in .Fig. .2 and provides, .as is well known, asource of vacuum.

The collar -59 is vertically adjusted upon the tube 51 so that it supports the rudder valve sec- ,tion designated generally 63 which in turn .sup-

ports the auxiliary eifect valve section designated generally by 64 so that the uppersurface of valvesectiontll bears against the lower surface of the main valve section .56. The nuts 51a in turn are adjusted so that the .upper surface of the main valve section 156.1ies against the lower surface of the attitude valve .65.

Tubeli'l passes .through the close-fitting centralopeningsteand 61 of the rudder valve sec- 11101163, through the central opening .68 of the auxiliary effectvalve section 54, theupper end of tube SI'being integral with the main casting '69 of the main valvesection .56.

Referring to Figs. 3 and 3A, the hollow upper end of tube 51 communicates with the chamber 10a formed in casting 69 by the generally circu- 'lar wall l'lland the bottom 69a of the casting. n-plate '1 l is fixedly attached to the top of casting 69 by means of the countersunk screws Na and a central hole 12 is present in the center of plate II. The bottom 69a of casting '69 is flat and solid with the exception of the ports 13, '14, I15 and 16, '83, 84,95 and 36 the functions of which will be later described. Integral with the central circular wall'll) of the casting 6,9 are the radially extendingwalls 11, 18, [9, 80, ill and 92. Consequently, the various parts of casting t9 and the plate "H form the chambers 83a, 84a, 13a 85a, 14a and 86a. The plate II has four openlugs-'89, '90, 9| and 92, each of-which opens into one of the respective chambers 83a, 84a, 95a and 86a. 'Ports 93, 84, 95 and-86 also open into the respective chambers 83a, 94a, 85a and 86a.

The flange 93a, integral with the casting 93 of the attitude valve section 95 is slightly less in diameter than the diameter of plate H upon which it rests. Flange 93a-is centered, in the neutral position, with respect to plate H. Integral with casting 93 are the four radial members-9d, 95, 96 and 91 which support the hollow central hub 98. The radial members 94, '95, 96 and .91 form four chambers Ha, l02a,-l93a and 10411 in the attitude valve section 65. A plate 9.9.isaifixed to the top of casting 15 by means of the countersunk screws 99a and this plate is solid except for thecentral opening Hill, the four openings 111L102, I03 and I94 placed therein, and the four smaller openings lillb, 102b, I031) and I941). It willbenoted that each of the openings 1.9!, 192, I93 and N14 is placed above one ofthe chambers Hlla, 12a, IUSa-and I940: formed by the radial partitions 94, :95, 96 and 9'! and .plate 99. The bottom of each of these chambers is open.

In view ,of the described structure, it will be app eci ted that the main centralchamber 10a formed in the main valve section 56by the casting 69 and associated parts is at all times evacuated by the turbine 62 by a predetermined amount less than the prevailing atmospheric pressure. Vacuum flows (to achieve simplicity of'expression vacuumrwill be spoken of as apositive rather "than a negative phenomenon) through the central "port 31.2 in the plate '1 l and through the centrabport .illllltin the. attitude valve section 65. The .plate 50 Jrests :at all times upon the circular plate .99 vaflixedto the top of casting 94 and :the cup 49 together with plate :50 forms a chamber in which vacuum .is present at all times.

When the control :stick139 isiin its neutral fore andaft aswell .as neutrallateral positions, the plate 59 is centered with respect to the plate .99 upon the top of casting .93 of the attitude valve section. In this-position the plate :59 covers the main ports I'M, :l.02,':li03.and 2104 in plate 99, but the four auxiliary ports HHb, 102b, .1931) and lll lb are not covered by this plate. Accordingly, .a limited amount of vacuum is, in-the'neutral position of stick :.39, admitted tothe chambers Lilla, Hl2a, Iflta and Ma. This same amount of vacuum passes throughithe -ports.89, 99, 19! and .92 of plate *H into the chambers 83a, a loatlla and 86a of the .main valvesection 56. The vacuum within chamberlstwipasses through the port 512 in the side of casting 69, and through the corn nector l l3 and a suitable flexible connection (not shown) to the front pitching bellows 1.8; the vacuum within chamber Ma passes through the port H4, connector atlfiiand'theflexible hose M6 to the left banking bellows 29; the vacuum within chamber a passes through the .port it! and a suitable connector and fiexible'hose not shown) to the rear pitching be'llowszl9; while the vacuum within chamberBBapassesrthrough'the port H8, connector H9 and flexibleihose I529 to the right banking bellows 21 Accordingly whenever the plate.=50 isin its neutral position by virtue of the control stick 39 being placed in :its neutral position, an equal amount of vacuum is present in all four of the main bellows l8, I9, 29 and 2!, and the fuselage 22 is positioned in the cruising position, the fore end :of the fuselage beingslightly raised, as shown.

However, whenever the student within the fuselage 22 pushes'the control stick 39 ahead, to simulate the movement which-he would impart to the control stick to cause the nose of the plane to drop, it Will be appreciated that the upper of the control stick 39 would move to the front in Fig. 3, causing the universal joint 44a to move to the rear. Plate 59 .similarlymoves, to the rear, and it will uncover the port llll in plate 99 by an amount dependent upon the angular movement of the control stick 39 ahead of its neutral position. At the same time, the plate so will uncover the port 193 by an amount dependent upon the same factor. Consequently, an increased amount of vacuumwill be applied to the port lei, to the chamber-Mia and port'89 to the chamber 83a in the-main valve section 56. This increased amount of vacuum will be applied through the .port .I I2, connector ---i F3 and flexible hose to the front pitching bellows i9, causing this *bellowsto collapse proportionately. At the same time, themovement of plate 59 will cover the port llllibin plate'99'so that vacuum will'no longer be applied to the chamber IO-3a. Instead, the movement of plate'fill will simultaneously uncover the port 10-3, admitting atmosphere to chamber 33a which is transmitted through the port'9l in platell to the chamber 85a, from whence it passes through the port [11, the provided connector and flexible hose to the rear pitching bellows 19. This bellow will consequently be expanded accordingly. Hence the contraction of bellows I and expansion of bellows I9 as a result of a forward movement of the upper end of control stick 39 will result in lowering of the nose of the fuselage 22.

On the other hand should the control stick 39 be moved to the rear, it will be appreciated that the plate 50 moves ahead in Fig. 3, opening the port I03 in plate 99 and admitting an increased amount of vacuum through the previously described chambers to the port H1 which connects with the rear pitching bellows I9. At the same time the port I0b is covered and port I0! is uncovered. Accordingly, atmosphere is admitted through the port I0! and the intermediate ports and chambers to the connector H3 which connects with the front pitching bellows I8. Accordingly, bellows I8 is expanded while bellows I9 is contracted, and the nose of fuselage 22 is raised.

It will therefore be appreciated that the pitching attitude of the fuselage 22 may be controlled by the student in the trainer to place the fuselage in any pitching attitude, within the limitations of the apparatus, by fore and aft movement of the control stick 39.

It should be noted that whenever the control stick 39 is moved directly fore or aft, the plate 50 does not'cover either of the ports IllZb or I042) or uncover either of the ports I62 or I04, and accordingly the lateral banking position of fuselage 22 is unaffected.

Assuming that the student moves the upper end of control stick 39 to the left of its neutral lateral position, it will be appreciated that the plate 50 is moved to the right of the fuselage, thereby uncovering the port I02 in plate 99 by an amount dependent upon the angular displacement of the control stick 39. An increased amount of vacuum will therefore be passed through the port I02 and the port 90 in plate II of the main valve section 56. Thi increased vacuum will manifest itself within chamber 84a and will pass through the port I I4, connector I I 5 and the flexible connector I I6 to the left banking bellows 20, causing this bellows to contract proportionately. Simultaneously therewith, the plate 50 will cover the auxiliary port I04b in plate 99, preventing the application of vacuum to the chamber W ld in the attitude valve section 65, but at the same time the movement of plate 50 will uncover the port I00 proportionately and atmosphere will enter the chamber Edda through this port and will enter the chamber 06a through the port 92 in plate II. Atmosphere then passes through the port H8 in casting 69 of the main valve section as well as through the intermediate connector H9 and flexible connection I20 to the right banking bellows 2 I. Accordingly, when the control stick 39 is moved to the left the left banking bellows 20 is collapsed proportionately and the right banking bellows 2| is expanded proportionately, causing the fuselage 22 to bank to the left.

If on the other hand, the student moves the upper end of control stick 39 to the right, the plate 50 moves toward the left side of the fuselage covering the port I021) and opening the port I02 to the atmosphere. Atmosphere passes through the port 90 into chamber 84a and thence through the port H4, connector H5 and connection H6 to the left banking bellows 20. Simultaneous therewith the movement of the plate 50 opens port I04 and vacuum passes through this port and port 92 to the chamber 86a in the main valve section 56. This increased vacuum passes through the port H8 and intermediate connecting elements to the right banking bellows 2|. Accordingly left banking bellows 20 is expanded by the atmosphere admitted thereto and right banking bellows 2I is collapsed by the increased amount of vacuum applied thereto, resulting in a banking of fuselage 22 to the right.

Again, it should be particularly noted that whenever the control stick 39 is moved directly to the left or right, the movement of plate 50 does not affect in any manner the ports IOI, IOIb, I03 or I03b, and consequently the pitching attitude of fuselage 22 is not affected.

Without a detailed explanation it should be understood that whenever the control stick 39 is moved ahead or to the rear of its neutral fore and aft position and is simultaneously displaced to the right or left of its neutral lateral position, the plate 50 will properly be moved relative to the plate 99 so that the main ports IOI, I02, I03, I04 and the auxiliary ports IOIb, I02b, I031) and I04b are covered or uncovered to properly place the fuselage 22 in a combined pitching and banking position, simulating the position in which a real airplane would be placed were its control stick moved accordingly.

Reference is now made to Fig. 3 where the rudder valve section 63 is seen to comprise a top I21 integral with the depending vertical cylindrical wall I20 which is of lesser diameter than the top I27, forming the flange I29. The top I2! is flat and solid with the exception of the ports I30, I3I, I32, I33 and I34, and the channel I 35. Integral with the top I2! and the cylindrical wall I28 is the vertical, cylindrically shaped wall I36 which is slightly larger in diameter than the hole 67 in the top I21 and which extends around the hole 61, except for the provision of the two vertical walls I31 and two vertical walls I38. An interior flange I39 is integral with the lower edges of the vertical walls I36 in order to form the hole 66, and integral with the flange I39 is the extension I 40 which merges with the vertical members I37 as well as with the vertical side wall I28. The vertical members I31 extend from the cylindrical wall I36 to the outer cylindrical wall I28. The outer wall of channel I35 depends vertically from the outer edge of flange I29 and is designated I 4|, it has two curved vertical end walls I42 integral with the outer wall while its inner wall is formed by the vertical cylindrical wall I36 which is integral with the end walls. The bottom of channel MI is solid and designated I43, this bottom being integral with the walls of the chamber. The vertical walls I38 are integral with the top I21 and with the cylindrical wall I28, as well as with the inner cylindrical wall I36, a notch I44 being cut in the inner cylindrical wall I36 so as to form a duct leading from within cylinder I36 to the channel I35. Integrally formed with the walls I38 and with the cylinder I36 is a suitable bottom (not shown) so as to render the passage from cylinder I36 to channel I35 airtight. A notch I45 is cut in the top of plate I21 so as to extend the top of channel I35 back toward the hole 61.

Inasmuch as tube 51 is inserted through the hole 66 and hole 61 in the rudder valve section 63, it will be appreciated that vacuum leaks through the holes 58 in tube 5] at all times so as to be present within cylinder I36. This vacuum is also present at all times within the spot ers port l3I-- which; in? tim top: in bctweenythe verticalnwalls I312, andiiis. at all times present within the channel I35 and'notch. Wiiinthe top I21. At the same tim e' atmosphere is always present within the ports I30, m,- Q33 and I34.

Turning. nowto a: detailed d'escription of the auxiliary effect valve section 64,- as shown in Figs. 3 and Sb, it will be recalled:that=this valve section has acentral hole: 6'8:-'which extends completely therethrough-ior the reception of the metal shaft 51'.

It will be notedth'atthe leaf 64-hasthree arcuate slots I46, I41 and-lwextending completely therethrough; these slotsbeing located and'separated'as" shown. Also placed in the top surface of section 64" are the two-counterbores I49 and I50, these counterbores extending only a portion of theway through the section 643 with the exception ofthecircular'ports I'5I and I52 which extend completely through section 64:

In the lower surface of leaf G4 are the two arcuate 'cmmterbores I53' and" I51 which extend upwardly part way through the section 64- and communicate with the arcuate counterbore I55 placed inthe top of section-64 by-means ofthe two-counterbores I56 and I511 Counterbores I55, I56 and I51 donot extend-completely through leafv 64.

When the lower surface-of" the auxiliary effect valve section it liesagainst the upper' surface of the rudder valve' section-63f andthe two sections are in their-neutraloperativepositions; the vacuum fill'ed port I oi section'tt lies between the two ports I5'I and I 5'Zof *thesection and slightly overlaps these two ports sothat a limited amount of vacuum isintroducedinto-the counterbores IAQ-and ISWinthe'upper surfaceof section 64. At the same time the port 1 3" in the lower surface of the main valvesection-BG is direct y above the middle-portion of counterbore I49 and por-tt'l' l is directly above-the center portionof counterbore I50: In thecentral'positions theatmosphere ports I3IJ'-and 132 are slightly-displaced from the lower ends oithe ports I5I' and I52 which extend completely through 1 the section 64.

Accordingly; when the sections 63, 64 and 56 are in their neutral operative positions, a limited amountof vacuum passesfrom the vacuum port I3I through the ports IEI and I52 and counterbores I49 and I50 throughthe ports I3 and I4 into the-.- chambers 13a: and: Ma; and thence through the ports .15. andl'lG, the connectors I58 and IE9 and flexibletubings llill' an'd I 6| to the turning motors 23.. Accordingly an equal'amount of vacuumis introduced to: the turning motors through the lines I50.- and I I5 I and these motors do not operate to rotate the fuselage 22;

In Fig. 3 it will be seen; that the cable I62 encirclesthe section 6-3; asshown, and is fastened thereto by suitable. meansv tovv prevent slippage, this cable also running upon: thepulleys; H54- and having its forward" left andr-right endsselectively connected to" the left: and right rudderpedals 26, Whenever the rudder: valve, section 63 is rotated clockwise inresponse to :a pressing forward of. the, right. rudder pedal,- .it: willbe appreciated that the. vacuum port I3I in section 63 will move out of engagementpwith the port- I52 in the sectionM- and that the atmosphere port I 3'2 willregister withthe port I52.- Accordingly, atmosphere will pass thlOllghthByDOrtS I 32'; I52, and counterbore I50 tothe port 14' and chamber 14a in the main valve section. 56. Atmosphere then passes. f rom: chamber 14m tl'rrougl'r the port 10 1-6; connector I59, and. flexiblehose [61 to the turning motors 231: At-thesame time the vacuum port I3I will: overlap'the-port lit in section 64 to. an increasingextent, and an increased amount of vacuum will be passed through port IiEI, counterbore I49, and port'.'t3cin the. main valvesection 56F to the chamber Illa-,1 from: which it passes to the. turning motors through the port 15'; connector. I:58, and flexible hose IN The increased amount of vacuum passing throughthe flexible hose. I60 and the passingyof atmosphere through theflexib'le hose lifittol theturning motors results in: an operation ot' these motors; such as to turn the fuselage 22. to theright.

On theother hand;v assuming that the rudder valve. section 63 is rotated counterclockwise. from its neutral positionyin: response to. a pressing forward of the lcttrudderpedal, the vacuum port I3I- in section Iii-Will. move away from the port I5I in. section 64 andwilicome into an increasingly overlappingaposition:with respect to. theport I52. in section 64; Accordingly, more. vacuum will be introduced .intothechamber Ma and to the turning motors 22 through theport. l6, connector I59 andflexihlehose- IGI Simultaneously therewith, the vacuum-port I:3I will move: out of engagement with the'port; l5.I andtheatmosphere port lat will move into engagementwith port I5I, whereupon atmosphere will be introduced to the chamber 13a. andyto the turning motors 23 through the port 15;, connector I58 :andhose I60. The introduction of atmosphere to the turning motors 23 through the-flexible hose I60 and the introduction of vacuum; toturning motors through the hose I61 in response to: a counterclockwise rotation. of the rudder. valve section. 63,; caused by a pressing forward: ofz the.- left rudder pedal, will result in a rotation-ref the fuselage 22130 the left.

It will be appreciated'that the rate of rota.- tion of fuselage. 2.2,wi1l, depcndupon the angular displacement of the rudder valve section 6.3 from its. neutral. position, this displacement in turn being in accordance-with the magnitude of the displacement of the rudder pedals 26 from their neutral position.

As is well known tothose skilled in the art, whenever a plane in actual flight is turned in either direction the plane automatically banks in the. direction of theturn. The previously described valve arrangement. is. such thatwhenever the fuselage 22. is turncdin either direction, vacuum and. atmosphere. are introduced into the banking bellows 2.0 and 2.I to automatically cause the fuselage 22 to bank. in. the direction of the turn.

When the two valvesections 6.3. and 64 are in their neutral operative. positions, the port I33 in section 63 lies immediatelybelow and between the adjacent ends. of. the two counterbores I 46 and I41 which. extend. completely through section 64-, and the atmosphere port I 34 is similarly positioned withrespect .tothe adjacent ends of the counterbores I41 and I' lfl. Also the vacuumfilled counterbore I35 in section 63, is below and slightly ofiset from the clockwise end of counterbore I46 and'the counterclockwise endof counterbore I48 in section 64. Also, when section 64 is neutrally positioned, the port 8,4 in section 56lies immediately above the center of counterbore M6 and port 86 in section. 5&- lies immediately above counterbore I48 Consequently, when the rudder valve section 63 is rotated clockwise inresponse to a pressing forward of the right rudder peda1-which movement results in a rotation of the fuselage 22 to the right--the atmosphere port I33 overlaps the counterbore I46 and atmosphere passes through port I33, centerbore M and port 84 into the chamber 85a, in the main valve section 55. It has previously been explained that this chamber is connected to the left banking bellows 25, and so atmosphere will be admitted to this bellows resulting in an expansion thereof. Simultaneously, the clockwise rotation of rudder valve section 63 will result in the clockwise end of the vacuum filled centerbore I35 overlapping the counterclockwise end of the counterbore I48 in the section 84. Vacuum will pass through counterbore I48 and the port 86 into the chamber 85a. in the main valve section 56. It has previously been explained that this chamber is connected to the right banking bellows ZI, and so vacuum will be introduced into that bellows, resulting in a contraction thereof. The expansion of the left banking bellows 2i! and simultaneous contraction of the right banking bellows III will result in a banking of fuselage 22 toward the right. The turning of the fuselage to the right also results in a banking to the right.

On the other hand, should the rudder valve section 53 be rotated counterclockwise in response to a pressing forward of the left rudder pedalwhich movement results in a rotation of the fuselage 22 to the left-the atmosphere port I34 will come into an overlapping position with a respect to the clockwise end of counterbore M3 in the section 54, and atmosphere will be fed through this counterbore and the port 56 into the chamber 85a in the main valve section 55. From this chamber the atmosphere will be introduced into through this counterbore and the port 84 into the chamber 84a in the main valve section. Vacuum will pass from this chamber into the left banking bellows 25. The introduction of vacuum into the left banking bellows 2i) and the introduction of atmosphere into the right banking bellows 2i will result in a banking of the fuselage 22 to the left. Consequently, whenever the fuselage 22 is turned to the left it also banks to the left.

It has been explained that the rate of rotation of the fuselage 22 depends upon the angular displacement of the rudder valve section 53 from its neutral position. At the same time it will be appreciated that the banking movement imparted to the fuselage 22 by a rotation of the rudder valve sectio 1 33 will also be proportional to the angular displacement of the rudder valve section from its neutral position. Therefore the fuselage 22 not only properly banks in the direction of the turn, but the angle of the bank is proportional to the rate of turning, accurately simulating the banking of a plane in actual flight caused by the turning thereof.

Referring again to the case of a plane in actual flight for purposes of comparison, whenever the plane is turning the nose of the plane tends to drop. This is commonly referred to in the art as automatic nose down with turn. The previously described valve arrangement also operates to lower the nose of the fuselage 22 whenever it is turning.

Referring to Fig. 3, the counterbore I35 and notch M5 are always filled with vacuum, and when the valve sections are in their neutral operative positions. the notch I 25 lies immediately below and slightly off-set from the adjacent ends of the counterbores I53 and I54 placed in the lower surface of section 64, and the port 83 in section 56 lies immediately above the center of counterbore I5 which is connected with counterbores I53 and I5 1. Also the atmosphere ports I33 and I34 lie below and are slightly off-set from the ends of countorbore Hi1 which passes through section 64, while port 35 in section 56 lies immediately above the center of counterbore I41. Whenever valve section 53 is moved in either direction from its neutral position, one of the ports I33 and I34 will come into overlapping relation with the counterbore M1 in section 54. Atmosphere will pass through counterbore I41 and port 35 into the chamber 85a in the main valve section as. It has been previously shown that this chamber is connected to the rear banking bellows IQ, and accordingly atmosphere will be introduced into that bellows. Simultaneously therewith whenever the rudder valve section is rotated in either direction from its neutral position, the vacuum filled notch hi5 will come into overlapping position with one of the counterbores I53 and I54 placed in the bottom of'the auxiliary effect of section 54. Ac-

= cordingly vacuum will pass-from the counterbore in question along the counterbore I56 or I51 into the counterbore I55 which engages the port 83 in the bottom of section 56. Vacuum will be introduced into the chamber 83a, and inasmuch as this chamber is connected to the front pitching bellows I8, vacuum will be introduced into that bellows. The simultaneous introduction of the vacuum into the front pitching bellows I8 and atmosphere into the rear pitching bellows I9 will result in a lowering of the nose of fuselage 22.

Accordingly the valve arrangement disclosed herein is such that the nose of the fuselage 22 is lowered whenever the fuselage 22 is turning to the left or right.

Also in the case of a plane in actual flight whenever the plane is banked to the left or right, the plane automatically turns in the direction of the bank. The previously described valve arrangement, together with the apparatus now to be described, operates to cause the fuselage 22 to automatically turn in the direction of the bank when the fuselage is banked.

Referring now to Fig. 4,the main spindle I4 and the main universal joint 28 are shown as well as the sub-frame members 21 of the fuselage 22. The sub-frame members 21 are affixed by means of bolts I12 to the plate I10 which is directly above the universal joint 28.

. The ears I13 which form a part of the universal joint 28 are integral with the plate I10 and the gimbal ring I14 is pivotally mounted within the ears I13 for pivoting about the axis I 15 which extends longitudinally of the fuselage 22. Amxed to the rear ear I13 is the integral extension I16, upon the outer end of which is pivotally mounted the bell crank I11, the fore end of which is pivotally attached to the link I18. The gimbal ring I14 is pivotally mounted in the upper end of the main spindle I4 for pivoting about the transverse axis I19 and the lower end of member I18 is pivotally attached to the stud I85, at a point on the transverse axis I19. The lower end of crank I11 has pivotally attached thereto the rear end of link I 85a, the forward end of which is pivotally attached to the auxiliary effect valve section 64 by means of the pin I BI, seen in Fig. 3.

In Fig. 4 it will be appreciated that whenever the fuselage 22 is banked toward the left, the

Of course this raising of the nose of the fuselage may be checked if desired by a forward movement of the control stick 39.

On the other hand, should the factor of assumed air speed be decreased, the operation of unit I82 in Fig. 5 will be reversed so as to move the disc 99 toward the head of the trainer an amount dependent upon the assumed decrease. Referring to Fig. 3 it will be appreciated that when disc 99 moves toward the head of the trainer, port H3312 is covered and port N13 is opened to the atmosphere, admitting atmosphere to the rear pitching bellows H3 in the manner previously described. Simultaneous therewith, the port H3! will be opened to the vacuum within cap 49 and vacuum will be admitted to the front pitching bellows [8.

The consequent collapsing of the front bellows l8 and expansion of the rear bellows l9 will result in a lowering of the nose of the fuselage.

Accordingly, the improved valve structure of my invention is adapted for use to affect the attitude of the fuselage according to the instant assumed air speed.

In view of the preceding disclosure it will be appreciated that the objects of this invention, as stated in the introduction hereof, have been met.

It will be appreciated by those skilled in the art that many changes may be made in the disclosed embodiment of my invention without departing from the substance thereof. Also, those skilled in the art will appreciate that a control column may be substituted for the control stick shown herein. All such changes are intended to be covered by the following claims.

I claim:

1. In a grounded aviation trainer of the type comprising a fuselage universally mounted with respect to a stationary base and four expansiblecontractible bellows connected to said fuselage for pivoting the same, a valve comprising a flat surface, two pairs of ports in said flat surface, the ports of each pair being located on opposite sides of the center of said fiat surface and a pneumatic connection between each port and a different one of said bellows, a plate arrangedto substantially cover all of said ports when the plate is neutrally positioned, a vacuum chamber formed in the center of said plate, a manually controllable member, and a connection between said manually controllable member and said plate arranged to move said plate in any direction radially of said fiat surface dependent upon the direction of movement of said manually controllable member, whereupon said ports are selectively opened into said vacuum chamber and vented to the atmosphere.

2. In a grounded aviation trainer of the type comprising a fuselage universally mounted with respect to a stationary base and four collapsibleexpansible bellows connected to said fuselage for pivoting the same, a valve assembly comprising a valve section having four circumferentially spaced and separate chambers, a pneumatic connection between each of said chambers and a different one of said bellows, a fiat surface and four ports in said fiat surface, one of each of said ports being in communication with a different one of said chambers, a plate having a vacuum chamber therein arranged to lie upon said fiat surface so as to substantially cover each of said ports whenv the plate is in its neutral position, a manually movable control, and a connection between said manually movable control and said valve assem- O my bly for changing the relative positions of said plate and ports according to the direction of movement of the manual control, whereupon said ports are selectively opened into said vacuum chamber and to the atmosphere.

3. In a grounded aviation trainer of the type comprising a fuselage universally and rotatably mounted with respect to a stationary base for pitching, banking and turning movements, a pneumatically operated turning motor for rotating the fuselage and four bellows for pitching and banking the fuselage, the combination of a valve assembly including a first valve section havin six separate circumferentially arranged chambers, a pneumatic connection between each of four of said chambers and a different one of said bellows and a pneumatic connection between each of the other two of said chambers and said turning motor, a port opening into each of said first four chambers through the top thereof and a port opening into each of the other two chambers through the bottom thereof, a second valve section placed below said previously mentioned section and having a vacuum chamber and a port leading therefrom as well as at least one atmosphere port, a plate having a vacuum chamber placed above the first four ports, said plate being arranged to substantially cover the said four ports in the top of said first valve section when the plate is neutrally positioned, a first manual control in the trainer connected to said plate for moving the same to selectively open said four ports into the vacuum chamber in said plate and to the atmosphere according to the direction of movement of the manual control, and a second manual control in the trainer connected to said second valve section for selectively causing the vacuum port and atmosphere port therein to register with the said two ports in the bottom of the first section.

4. In a grounded aviation trainer of the type comprising a fuselage pivotally mounted with respect to a stationary base and a pair of expansible-contractible bellows connected to said fuselage for pivoting the same, a valve assembly comprising a flat surface, a pair of ports in said flat surface, a connection between one of said ports and one of said bellows and a connection between the other of said ports and the other of said bellows, a plate arranged to substantially cover both of said ports when said plate and said flat surface are neutrally positioned one with respect to the other, a vacuum chamber, a manually controllable member, a movable member forming a part of said trainer, a means forming a part of said trainer for positioning said movable member in accordance with the instant assumed air speed of said trainer, means interconnecting said manually controllable member and said valve assembly for changing the relative positions of said fiat surface and said plate and means interconnecting said valve assembly and said movable member for changing the relative positions of said fiat surface and said plate, whereupon said ports are selectively opened into said vacuum chamber and the atmosphere according to the combined positions of said manually controllable member and the instant assumed air speed.

i 5. In a grounded aviation trainer of the type comprising a fuselage universally mounted with respect to a stationary base and four expansiblecontractible bellows connected to said fuselage for pivoting the same, a valve comprising a fiat surface, two pairs of ports in said fiat surface, and a pneumatic connection between each port 17 and a diiferent one of said bellows, a plate arranged to substantially cover all of said ports when the plate is neutrally positioned, a vacuum chamber formed in said plate, a manually controllable member, and a connection between said manually controllable member and said plate arranged to move said plate in any direction radially of said flat surface dependent upon the direction of movement of said manually controllable member, whereupon said ports are selectively opened into said vacuum chamber and vented to the atmosphere.

6. In a grounded aviation trainer of the type comprising a fuselage universally and rotatably mounted with respect to a stationary base for pitching, banking and turning movements, a pneumatically operated turning motor for rotating the fuselage and four bellows for pitching and banking the fuselage, the combination of a valve assembly including a first valve section having six separate circumferentially arranged pneumatic passages, a pneumatic connection between each of four of said passages and a different one of said bellows and a pneumatic connection between each of the other two of said passages and said turning motor, a second valve section placed below said previously mentioned section and having a vacuum passage and an atmosphere passage, a plate having a vacuum chamber placed above the first valve section, said plate being arranged to substantially cover the said four passages in the top of said first valve section when the plate is neutrally positioned, a first manual control in the trainer connected to said plate for moving the same to selectively open said four passages into the vacuum chamber in said plate and to the atmosphere according to the direction of movement of the manual control, and a second manual control in the trainer connected to said second valve section for selectively causing the vacuum passage and atmosphere passage therein to register with the said two other passages in the said first section.

7. In a grounded aviation trainer of the type comprising a fuselage universally and rotatably mounted with respect to a stationary base for pitching, banking and turning movements, a

18 pneumatically operated turning motor for rotating the fuselage, four pneumatically operated bellows for pitching and banking the fuselage, one of a plurality of separate pneumatic lines connected to each of said bellows and a pair of pneumatic lines connected to said turning motor, valve means for controlling the pneumatic pressure in each of said pneumatic lines, said valve means including a distributing member having a flat surface and six pneumatic passages therein each of Which passes through said fiat surface and is in communication with a difierent one of said pneumatic lines, a first movable valve section having two fiat surfaces one of which is placed against the fiat surface of the distributing member and a plurality of pneumatic passages therethrough, a second movable valve section having a fiat surface placed against the other fiat surface of the first valve section and a plurality of pneumatic passages therein, a source of vacuum connected to certain of the pneumatic passages in said second valve section and certain of the pneumatic passages in said second valve section being vented to the atmosphere,

and manually operable means in the fuesalge connected to each of the movable valve sections for selectively operating the same to regulate the passage of vacuum and atmosphere from the second movable valve section through the first movable valve section to the said distributing member and pneumatic lines.

SAMUEL ARTHUR DOUGLAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 508,247 Schwab Nov. 7, 1893 1,825,462 Link Sept. 29, 1931 2,082,410 McCauley June 1, 1937 2,099,857 Link Nov. 23, 1937 2,144,616 Carlson Jan. 24, 1939 2,271,331 Elliott Jan. 27, 1942 2,385,016 Link Sept. 12, 1944 

